397661 has 4 divisors (see below), whose sum is σ = 433824. Its totient is φ = 361500.

The previous prime is 397643. The next prime is 397673. The reversal of 397661 is 166793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 397661 - 2⁶ = 397597 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (397361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18065 + ... + 18086.

It is an arithmetic number, because the mean of its divisors is an integer number (108456).

2³⁹⁷⁶⁶¹ is an apocalyptic number.

It is an amenable number.

397661 is a deficient number, since it is larger than the sum of its proper divisors (36163).

397661 is a wasteful number, since it uses less digits than its factorization.

397661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36162.

The product of its digits is 6804, while the sum is 32.

The square root of 397661 is about 630.6036790251. The cubic root of 397661 is about 73.5367333008.

The spelling of 397661 in words is "three hundred ninety-seven thousand, six hundred sixty-one".